Clip rings are commonly used to removably secure shafts and similar structures in bearing and other cylindrical cavities.
Typically, the clip ring made of steel or other resilient material forms an open loop that can be captured in a circular depression along a shaft. The ring is circumferentially compressed to a point where the gap in the loop of the ring is nearly closed, and the entire ring is completely nested in the circular depression of the shaft. The shaft is then inserted into a cylindrical bearing that has a circular groove commensurate with the ring. When the ring reaches the groove, it circumferentially expands to a degree sufficient to enter the groove without completely leaving the circular depression of the shaft. The shaft is thus axially immobilized into the bearing.
In some single or multi-conductor electrical connectors, the terminal pins must be accurately positioned and oriented to precisely and intimately engage the corresponding terminals of the mating connector. Yet, it is desirable that each pin be removable for attachment by crimping or soldering to a conductor, or for reassignment of a lead to a different position within the same connector. Due to the extreme miniaturization of certain modern multi-conductor connectors, it is practically impossible to solder or crimp a wire to a terminal pin while it is mounted on the connector body.
As exemplified in the prior art structure illustrated in FIGS. 1 and 2, a clip ring 1 is used to mount a terminal pin 2 in the body 3 of a single or multi-conductor connector. In its normal state, the clip ring 1 has a circumferential gap 4 and an outer diameter D which exceeds the outer diameter P of the terminal pin 2, which outer diameter is, in turn, larger than the inner diameter d of the ring. The ring is circumferentially expanded to engage upon, and slide along the terminal pin body until it snaps into a circular depression 5. The front end of the ring has a beveled area 6. which circumferentially compresses the ring into the depression 5 when the pin is pushed into its circular holding channel 7 whose diameter C is slightly larger than the diameter P of the terminal pin.
When the ring reaches a circular groove 8 in that channel, it circumferentially expands to its normal size, thus locking the pin into the connector body 3.
The terminal pin can only be removed by means of a tubular tool, not shown on the drawing. That tool has a thickness no greater than the difference between the diameter C of the holding channel and that P of the terminal pin. The tool acts upon the beveled front area 6 of the clip ring to compress it back into the depression 5, so that the terminal pin can be extracted.
The difference in the terminal pin and holding channel diameters, coupled with the fact that once expanded into the circular groove, the ring does not tightly contact the terminal pin, creates a certain degree of instability and misalignment. This makes it difficult to insert the connector into its mating structure without a great deal of wiggling maneuvers.
The problem can only be partially palliated by providing a tighter fit between the pin and the back section 9 of the holding channel that does not need to be penetrated by the removing tool.
If the clip ring and connector bodies are not manufactured to exacting tolerances, the clip ring can slip away from its circular groove when axial pressure is applied to the pin. This problem tends to particularly affect certain miniature connectors.
This invention results from an attempt to find a solution to the aforesaid shortcomings of the prior art electrical connectors.